Standard internal combustion engines rely upon a pressure differential to move the fuel/air mixture into the combustion chamber. During the intake stroke of the piston of a conventional engine, the piston recedes in the cylinder bore, away from the fuel/air inlet port. Simultaneously, a valve is opened at the inlet port. The receding piston creates a partial vacuum in the combustion chamber, causing a pressure differential to develop between the combustion chamber and the outside atmosphere. As a result, air is drawn through the carburetor, through the intake manifold, past the intake valve and into the combustion chamber. As the air passes through the carburetor, fuel is mixed with the air to create a misty fuel/air mixture. It is this fuel/air mixture which is drawn into the combustion chamber and is ignited to provide energy.
The nature and quality of the combustion of the fuel/air mixture in the combustion chamber depends upon numerous factors. One of the most significant of these factors is the degree to which the fuel droplets released by the carburetor are atomized and eventually vaporized on their way to the combustion chamber. Ideally, the fuel/air mixture in the combustion chamber should be a gas consisting of a combination of air fuel in the gaseous state. Fuel in the liquid state, suspended in the combustion chamber as a mist or droplets, will not ignite and yield the resulting thermal energy as effectively as totally vaporized, gaseous fuel.
The power generating capability of a given size combustion chamber also depends upon a number of factors. Among the most important of these factors is the quantity of the fuel/air mixture present in the combustion chamber at the end of the intake cycle. Injection of a large amount of fuel/air mixture into the combustion chamber results in an increase in the power output of the chamber. However, in a conventional engine, the need to maximize that quantity and the need to maximize fuel vaporization within the combustion chamber poses a problem. Designs meant to improve vaporization often inhibit the free flow of fuel/air mixture into the combustion chamber.
Various intake system designs have been proposed which are intended, among other things, to improve the vaporization of the fuel. These designs generally either provide a needlessly complicated apparatus or neglect to consider the impact that the design will have on the quantity of fuel/air mixture reaching the combustion chamber by the end of the intake stroke.
U.S. Pat. No. 958,759, issued to Nilson in 1910, discloses a poppet valve for a combustion engine. The valve includes a stem mounted to a thin curved head. A plurality of curved ribs extend from the stem to a flange on the valve head. The valve construction disclosed by Nilson is designed to increase the strength of a valve and at the same time reduce the weight of the valve. The curved ribs provide a greater radiating surface to prevent overheating of a valve. However, the flange of the valve head and the ribs inhibit the free flow of the fuel/air mixture into a combustion chamber. As the fuel/air mixture is drawn into a combustion chamber, the ribs and flange impede the velocity of the mixture and reduce vaporization.
Another poppet valve for an internal combustion engine is disclosed in British Pat. No. 204l443A published in 1980. The valve includes a plurality of helical vanes extending away from the stem. The vanes project upwardly from the valve head and are designed to create a swirling flow of the fuel/air mixture in a combustion chamber. However, the height of each vane impedes the velocity of the mixture as it passes over the valve head, thereby reducing vaporization.
It is, therefore, an object of the present invention to improve vaporization of the fuel/air mixture in the combustion chamber without reducing the flow of the fuel/air mixture to the chamber. A related object is the improvement of the distribution of vaporized fuel within the combustion chamber. A further object is to provide a swirling motion to the fuel/air cloud in the chamber. These effects of the present invention provide improved fuel efficiency and reduced emissions without a power loss resulting from inhibited flow of the fuel/air mixture to the combustion chamber.